Effects of Different Lung Volume Conditions on Closed Quotient, Vocal Fundamental Frequency and Relative Intensity in Vocally Untrained Female Speakers.

The objective of this study was to determine the relationship between lung volume (LV) conditions and vocal fold vibratory patterns using measurements of closed quotient (CQ), fundamental frequency (F0) and relative vocal intensity. Forty-three healthy and vocally untrained females were asked to produce the vowel /a/ following breathing instructions that cued for higher, habitual, or lower LV conditions. Closed quotient was measured by electroglottography (EGG) and analyzed using criterion-level method of 25%. An average of CQ, F0 and relative vocal intensity were obtained. No significant difference was observed in CQ between cued LV conditions; however, there was a trend for CQ to increase in the cued high LV condition. Relative vocal intensity and F0 differed significantly across all conditions with higher F0 and relative vocal intensity observed at the high LV condition. These findings suggested that the use of different cued LVs did not have a significant impact on CQ. This may have been due to (1) the phonatory task, (2) variability in responses to the breathing instructions between individuals, and (3) the measurement of CQ. However, F0 and relative vocal intensity were significantly influenced by the LV. This offers a possible alternative approach in cueing pitch and loudness in singing and voice therapy. [ABSTRACT FROM AUTHOR]